Coiro V, Volpi R, Marcato A, Bertoni P, Cavazzini U, Caffarri G, Capretti L, Rossi G, Chiodera P
Institute of Internal Medicine, School of Medicine, University of Parma, Italy.
Psychoneuroendocrinology. 1992 Nov;17(6):667-71. doi: 10.1016/0306-4530(92)90025-3.
The possible involvement of GABAergic B receptors in the control of LH and ACTH/cortisol secretion in response to naloxone was evaluated in seven normal men. Subjects were tested with naloxone (4 mg IV bolus plus 10 mg infused over 2 hr) with or without previous treatment with the gamma-aminobutyric acid (GABA)-ergic B receptor agonist, baclofen (5, 10 or 15 mg PO 30 min before naloxone). In additional experiments, six normal men were tested with 15 mg baclofen or placebo 30 min before a 2-hr infusion of normal saline. Plasma cortisol levels rose 70% in response to naloxone. The naloxone-induced cortisol rise was not modified by pretreatment with baclofen (5, 10 or 15 mg). Plasma LH concentrations rose 66% in response to naloxone. When the lowest dose of baclofen (5 mg) was administered, the LH response to naloxone remained unchanged. In contrast, 10 mg baclofen produced a significant reduction, and 15 mg baclofen completely abolished the naloxone-induced LH rise. The administration of baclofen or placebo alone did not change basal plasma levels of cortisol and LH. These data suggest that, in normal men, GABA B receptors participate in the endogenous opioidergic control of LH secretion, but not of ACTH/cortisol secretion.
在七名正常男性中评估了γ-氨基丁酸（GABA）能B受体在纳洛酮作用下对促黄体生成素（LH）和促肾上腺皮质激素/皮质醇分泌控制中的可能参与情况。受试者接受纳洛酮测试（静脉推注4毫克加在2小时内输注10毫克），在使用或不使用γ-氨基丁酸（GABA）能B受体激动剂巴氯芬（在纳洛酮前30分钟口服5、10或15毫克）预处理的情况下。在额外的实验中，六名正常男性在输注2小时生理盐水前30分钟接受15毫克巴氯芬或安慰剂测试。纳洛酮使血浆皮质醇水平升高70%。巴氯芬（5、10或15毫克）预处理并未改变纳洛酮诱导的皮质醇升高。纳洛酮使血浆LH浓度升高66%。当给予最低剂量的巴氯芬（5毫克）时，LH对纳洛酮的反应保持不变。相反，10毫克巴氯芬使反应显著降低，15毫克巴氯芬完全消除了纳洛酮诱导的LH升高。单独给予巴氯芬或安慰剂并未改变皮质醇和LH的基础血浆水平。这些数据表明，在正常男性中，GABA B受体参与了LH分泌的内源性阿片肽能控制，但不参与促肾上腺皮质激素/皮质醇分泌的控制。
